This DD Style LED lamp can save energy up to 65% comparing with traditional Fluorescent 2D fittings. With a long life of 30000 hours, these are 3 times longer lasting than with Fluorescent 2D Lamps 12W 4000K Cool White lamp with 30,000 hour average lamp life Direct retro fit replacement for DD flourescent lamps Compatible with Kosnic’s KTC27EME-DD emergency module. Instant start. Mercury free. Ideal for schools, hospitals, clubs, warehouses, cold rooms, stairways and corridors ect